Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bacterial DNA reduces inflammation in mice

03.02.2004


DNA from inactivated "probiotic" bacteria triggers a specific anti-inflammation immune response in mice with experimental colitis, researchers supported by the NIH’s National Institute of Allergy and Infectious Diseases (NIAID) have discovered. Led by Eyal Raz, M.D., of the University of California, San Diego (UCSD), the investigators provide a possible explanation for the observed benefits of consuming probiotics, supplements from bacteria and other microbes, regarded by some as helpful in maintaining or restoring intestinal health. Knowing how probiotics work could give scientists a way to identify and select which probiotic bacteria might be effective against such human ailments as inflammatory bowel disease (IBD).



Probiotics have shown promise for treating such IBDs as Crohn’s disease and ulcerative colitis, both of which cause periodic intestinal inflammation. But scientists have had many theories of how these mixtures of "good" bacteria work, notes Marshall Plaut, M.D., of NIAID’s Division of Allergy, Immunology and Transplantation. Plausible theories suggested that proliferation of the living bacteria either generated helpful metabolic products or crowded out "bad" intestinal bugs. Prior to this study, the general thinking about probiotics, which include bacteria like those found in yogurt, has been that they mediate their effects through some kind of non-specific action, adds Dr. Plaut.

Dr. Raz and his colleagues, whose work is published in the February 2004 issue of the journal Gastroenterology, irradiated a commercially available probiotic preparation, halting bacterial proliferation, but preserving its DNA. When given to mice, the irradiated probiotics performed as well as live bacteria in reducing inflammation. They also found that purified probiotic bacterial DNA alone similarly reduces inflammation in mice with experimentally induced colitis.


The researchers also showed that probiotic DNA acts in a specific way by activating a defined element within the innate immune system. In animals, including humans, components of the innate immune system play complementary roles in initiating, then halting, inflammation. Improperly regulated inflammation is one symptom of IBDs.

An innate immune system protein called TLR9 is a pivotal player in the chemical signaling chain that slows inflammation. In a series of experiments, the UCSD team showed that probiotic DNA exerts its effects through TLR9. Indeed, mice without the gene for TLR9 protein cannot benefit from probiotics, either living or irradiated, or from probiotic DNA.

Taken together, insights into mechanisms of probiotic activity open new possibilities for probiotic therapies. For example, say some researchers, purified probiotic DNA or irradiated probiotics may be safer than viable preparations, and could be used by people with compromised immune systems.

Dr. Raz also received support for this research from the National Institute of Diabetes and Digestive and Kidney Diseases, a part of the NIH.


NIAID is a component of the National Institutes of Health (NIH), which is an agency of the Department of Health and Human Services. NIAID supports basic and applied research to prevent, diagnose and treat infectious and immune-mediated illnesses, including HIV/AIDS and other sexually transmitted diseases, illness from potential agents of bioterrorism, tuberculosis, malaria, autoimmune disorders, asthma and allergies.

Reference: D Rachmilewitz et al. Toll-like receptor 9 signaling mediates the anti-inflammatory effects of probiotics in murine experimental colitis. Gastroenterology. (Feb. 2004) DOI:10.1053/j.gastro.2003.11.019.

Anne A. Oplinger | EurekAlert!
Further information:
http://://www.niaid.nih.gov/

More articles from Health and Medicine:

nachricht Collagen nanofibrils in mammalian tissues get stronger with exercise
14.12.2018 | University of Illinois College of Engineering

nachricht New discoveries predict ability to forecast dementia from single molecule
12.12.2018 | UT Southwestern Medical Center

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Data use draining your battery? Tiny device to speed up memory while also saving power

14.12.2018 | Power and Electrical Engineering

Tangled magnetic fields power cosmic particle accelerators

14.12.2018 | Physics and Astronomy

In search of missing worlds, Hubble finds a fast evaporating exoplanet

14.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>